Using a small diameter exit hose to improve delivery of liquid through a valve on a nutrient or chemical application system of an agricultural machine

ABSTRACT

A mobile agricultural machine has a valve controlled to apply liquid material to a field. An application assembly defines a conduit from the valve to a distal application tip. The application assembly includes a distal conduit section that has an inner diameter that is smaller than an inner diameter of a more proximal conduit section, that is closer to the valve, than the distal tip of the application assembly.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on and claims the benefit of U.S.provisional patent application Ser. No. 62/648,190, filed Mar. 26, 2018,the content of which is hereby incorporated by reference in itsentirety.

FIELD OF THE DESCRIPTION

The present description relates to agricultural machines. Morespecifically, the present description relates to controlling liquidapplication using an agricultural machine.

BACKGROUND

There is a wide variety of different types of agricultural machines thatapply a liquid material. Some such agricultural machines includesprayers, tillage machines with side dressing bars, air seeders andplanters that have row units.

As one example, a row unit is often mounted on a planter with aplurality of other row units. The planter is often towed by a tractorover soil where seed is planted in the soil, using the row units. Therow units on the planter follow the ground profile by using acombination of a downforce assembly that imparts a downforce on the rowunit to push disc openers into the ground and gauge wheels to set depthof penetration of the disc openers.

Row units can also be used to apply liquid material to the field (e.g.,to the soil, to a plant, to a seed, etc.) over which they are traveling.In some scenarios, each row unit has a pulse-controlled valve (such as avalve controlled using a pulse width modulated signal) that is coupledbetween a source of liquid material, and an application assembly. As thevalve is pulsed, liquid passes through the valve, from the source to theapplication assembly, and is applied to the field. This type ofmetering, using a pulsed control signal, induces a pulsing dynamic intothe flow of the liquid material. Even where the valve is not controlledusing a pulsed control signal, pulsation can be introduced through othersources, such as a pump.

The discussion above is merely provided for general backgroundinformation and is not intended to be used as an aid in determining thescope of the claimed subject matter.

SUMMARY

A mobile agricultural machine has a valve controlled to apply liquidmaterial to a field. An application assembly defines a conduit from thevalve to a distal application tip. The application assembly includes adistal conduit section that has an inner diameter that is smaller thanan inner diameter of a more proximal conduit section, that is closer tothe valve, than the distal tip of the application assembly.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter. The claimed subject matter is not limited to implementationsthat solve any or all disadvantages noted in the background.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of one example of a planting machine.

FIG. 2 shows a side view of one example of a row unit of the plantingmachine illustrated in FIG. 1.

FIGS. 3A-3C are pictorial and schematic illustrations showing oneexample of how an accumulator can be deployed on the row unit shown inFIG. 2.

FIGS. 4A and 4B are pictorial and schematic illustrations showing oneexample in which an expandable hose can be used as an accumulator.

DETAILED DESCRIPTION

The present description proceeds with respect to a number of differentexamples. In one example, an application assembly has an exit hose thathas an inner diameter that is smaller than the inner diameter of otherhose sections in the application assembly. In another example, anaccumulator is used with the application assembly to smooth pulsations.In yet another example, the application assembly has both theaccumulator and the small diameter exit hose. These and other examples,and combinations of examples, are contemplated herein. Also, the presentdescription proceeds with respect to the examples being deployed on arow unit of a planter. They could just as easily be deployed on asprayer an air seeder, or other piece of agricultural equipment that isused to apply a liquid nutrient or chemical.

FIG. 1 is a top view of one example of an agricultural planting machine100. Machine 100 is a row crop planting machine that illustrativelyincludes a toolbar 102 that is part of a frame 104. FIG. 1 also showsthat a plurality of planting row units 106 are mounted to the toolbar102. Machine 100 can be towed behind another machine, such as a tractor.FIG. 1 shows that liquid material can be stored in a tank 107 and pumpedto valves 109 through a supply line 111. In one example, a pulsing valvecontrol system 113 controls valves 109 using, in one example, a pulsewidth modulated control signal. The flow rate through valve 109 is basedon the duty cycle of the control signal (which controls the amount oftime the valves are open and closed).

FIG. 2 is a side view showing one example of a row unit 106, with valve109 and system 113 shown as well. Row unit 106 illustratively includes achemical tank 110 and a seed storage tank 112. It also illustrativelyincludes a disc opener 114, a set of gauge wheels 116, and a set ofclosing wheels 118. Seeds from tank 112 are fed by gravity into a seedmeter 124. The seed meter controls the rate at which seeds are droppedinto a seed tube 120 or other seed delivery system, such as a brushbelt, from seed storage tank 112. The seeds can be sensed by a seedsensor 122.

In the example shown in FIG. 2, liquid material is pumped through supplyline 111 to an inlet end of valve 109. Valve 109 is controlled bycontrol system 113 to open and close to allow the liquid to pass fromthe inlet end of valve 109 to an outlet end. System 113 uses a pulsewidth modulated signal to control the flow rate through valve 109.

As liquid passes through valve 109, it travels through an applicationassembly 115 from a proximal end (which is attached to an outlet end ofvalve 109) to a distal tip (or application tip) 117, where the liquid isdischarged into a trench, or proximate a trench, opened by disc opener142 (as is described in more detail below). Because of the pulsedoperation of valve 109, this can induce pulsed flow through applicationassembly 115. Even when the valves 109 are not operated with a pulsedcontrol signal, pulsation can be induced in the flow from other sourcesas well, such as from the pump. Thus, this can induce discontinuous andpulsed dispensing of liquid through tip 117.

Therefore, in one example, an accumulator 119 is added to applicationassembly 115, between valve 109 and dispensing tip 117. The accumulatoris illustratively inline, downstream of the valve 109 (between valve 109and tip 117). Thus, when valve 109 opens, the liquid under pressure isintroduced into the assembly 115 and the pressure in the assembly 115increases and is absorbed by accumulator 119. When valve 109 closes, thepressure absorbed by accumulator 119 is released. Accumulator 119 thusabsorbs and smooths the pulses in the flow of liquid material beingapplied.

In another example, application assembly 115 is formed of a plurality ofdifferent hose sections, between valve 109 and tip 117. The distal-mosthose section can have a smaller inner diameter than the more proximalhose section(s). As is discussed in more detail below, this tends tolengthen the overall pulse exiting the hose to improve coverage.

In yet another example, the accumulator 119 can be used in conjunctionwith the smaller diameter distal hose section. This further addressesthe pulsation in the system.

Before describing the operation of row unit 106 in more detail, a briefdescription of the operation of accumulator 119 will first be provided.FIGS. 3A-3C show accumulator 119, and its operation, during differentphases of the control of valve 109. In FIG. 3A, it assumed that valve109 is closed. A compressible fluid, such as air, is contained withinaccumulator 119. The direction of fluid flow through applicationassembly 115 (when valve 109 is open) is indicated by arrow 151. Thus,it can be seen that accumulator 119 is downstream of valve 109 in thedirection of fluid flow.

It can be seen in FIG. 3B that valve 109 is now opened. The fluid pumpedfrom supply line 111 through valve 109 may be provided at a wide varietyof different pressures, such as pressures in a range of 10-150 psi. Whenvalve 109 opens, this creates a high pressure on the downstream side ofvalve 109 which compresses the compressible fluid in accumulator 119.The liquid being pumped through valve 109 thus fills a space withinaccumulator 119, having compressed the compressible fluid (e.g., theair) in accumulator 119. The same type of operation occurs when thepressure pulse is introduced based on the operation of a pump upstreamof valve 109, or from another source.

Then, valve 109 is closed again. As the liquid exits tip 117, thiscreates a lower pressure on the downstream side of valve 109, at theinput to accumulator 119. An example of this is shown in FIG. 3C. Whenthat occurs, the compressible fluid in accumulator 119 then againexpands, pushing the liquid which was in accumulator 119 out, so that itcan pass downstream through the conduit defined by application assembly115 and be dispensed in the seed trench through distal tip 117.

Accumulator 119 can take a wide variety of different forms. Forinstance, it can be an air only accumulator in which the compressiblefluid in accumulator 119 is air. It can be an air or nitrogenaccumulator where the compressible fluid is separated from the liquidbeing pumped through valve 109 by a membrane, such as a diaphragm orbaffles, or a closed cell foam inserted into the flow.

Referring again to FIG. 2, accumulator 119 can also be incorporated intothe application assembly 115, itself. In one example, applicationassembly 115 defines a conduit from the outlet end of valve 109 to thedistal tip 117. It can include multiple different hose sections. Thepresent description proceeds with respect to two or three different hosesections but this is only on example. Other numbers of hose sections (orconduit sections) can be used as well.

In one example, application assembly 115 can include first expandablehose section 125, and second expandable hose section 127 that is distalfrom hose section 125 (e.g., located more toward distal tip 117 thanhose section 125) and separated from hose section 125 by an orificemember 129. In the example shown in FIG. 2, application assembly 115also has a smaller diameter hose section 131 connected to a distal endof hose section 127. Hose section 131 has an inner diameter which issmaller than the inner diameter of hose sections 127 and 125. Hosesection 131 (and orifice member 129) can also be made to be lessexpandable (or non-expandable) under the operating pressure of theliquid passing therethrough (e.g., 10-150 psi) relative to hose sections125 and 127. In addition, the durometer of hose sections 125 and 127need not be the same. One can expand more or less under the samepressure than the other. Also, hose section 131 and distal tip 117 canbe a single piece or separate pieces. Distal tip 117 can be part of hosesection 131 or a separate member. Where distal tip 117 is a separatemember, it can be used instead of along with hose section 131. These andother configurations are contemplated herein.

FIGS. 4A and 4B show one example of the operation of applicationassembly 115 when configured as shown in FIG. 2. Similar items to thoseshown in FIG. 2 are similarly numbered. In FIG. 4A, it is assumed thatvalve 109 is closed, so that there is relatively low pressure withindispensing assembly 115. It can be seen that the inner diameter of hosesection 131 is smaller than the relaxed inner diameter of hose sections125 and 127. The direction of fluid flow when valve 109 is open is againillustrated by arrow 151.

In FIG. 4B, it is assumed that valve 109 is opened. Because hosesections 125 and 127 are expandable (e.g., they are shown as beingradially expandable-in a direction transverse to their longitudinalaxes, or transverse to the direction of fluid flow 151, but they couldbe longitudinally expandable instead, or in addition) and because hosesection 131 is not expandable (or is less expandable) under the sameinternal pressures, the higher pressure introduced into those hosesections causes the hose sections 125 and 127 to expand, thus acting asan accumulator. Therefore, the more expandable hose sections included inthe dispensing assembly (or application assembly) 115, the greater thepulse suppression will be. Hose sections 125 and 127 are shown expandingradially, but they could just as easily expand longitudinally orradially and longitudinally. When the valve 109 is again closed, thehose sections 125 and 127 again compress against the lower pressure ofthe liquid passing through them, to dispense it through the exit hosesection 131 and dispensing tip 117.

It will be noted that, while multiple expandable hose sections 125 and127 are shown in FIGS. 2 and 4, connected by an orifice member 129,other configurations are contemplated herein. For instance, a singleexpandable hose section may be provided as the accumulator, or more thantwo may be provided, with additional restrictions or orifice members 129disposed between them. The lengths of the expandable hose sections 125and 127 may vary, depending upon the pressure of the pressurized fluidthat is to pass through them during a high pressure phase, based on adesired flow rate, and based upon other desired applicationcharacteristics.

Similarly, the inner expandable diameter (when in a relaxed position) ofhose sections 125 and 127 as well as the relatively fixed innerdiameters of exit hose 131, orifice member 129 and dispensing tip 117(when it is a separate piece from exit hose 131), may be based upon thepressures of the liquid to be carried through them, the desired flowrate and dispensing characteristics, among other things. In one example,the fluid passing through valve 109 is illustratively at a pressure in arange of 10-150 psi. In that case, the inner diameter of the exit hosesection 131 and dispensing tip 117 may be in a range of approximately2-4 mm and exit hose 131 and tip 117 may be formed so that the innerdiameter is fixed under the range of internal pressures, exerted by theliquid (e.g., regardless of whether valve 109 is open or closed). Theinner diameter of the accumulator hose sections 125 and 127 may be in arange of 6.35-12.7 mm. The inner diameter of orifice member 129 may bein a range of 0.7-4.5 mm.

The amount by which each accumulator hose length 125 and 127 expandsgiven an input pressure, may vary widely based upon the particularapplication characteristics desired, based upon the length of theexpandable hose sections and the number of expandable hose sections,among other things. In one example, the expandable hose sections have adurometer which permits them to expand by a desired amount underpressurized fluid being introduced through valve 109. Also, in oneexample, the durometer of exit hose 131 (or distal tip 117, or both) issuch that it does not significantly expand under those pressures. Thisacts to remove or at least smooth out the pulses in the fluid flowingthrough dispensing assembly 115. It will also be noted that theparticular configuration of dispensing assembly 115 may vary among therow units 106 across planter 100. They need not all be the same,although they can be the same as well. Further, the particularconfiguration of hose lengths 125 and 127 can be the same or different.There can be more or fewer hose sections and more or fewer orificemembers. Exit hose 131 can be eliminated when only distal tip 117 isused. These and other configurations are contemplated herein.

Further, it will be noted that the smaller diameter exit hose 131 and/ordistal tip 117 can be used alone (without an accumulator) or with anaccumulator. By providing an exit hose 131 and/or tip 117 with a smallerinner diameter than hose sections 125 and 127, and being formed of amaterial that is less expandable under the pressure of the liquidflowing through them than the more proximal hose sections (or beingsubstantially inexpandable under that pressure) a number of additionaladvantages can be obtained. When combined with the pulse width modulatedoperation of control valve 109 (or when pulsation is induced by anothersource), exit hose section 131 and/or tip 117 serve to lengthen theoverall pulse exiting the hose, thus providing better in-trench coverage(or other coverage) of liquid material. It can also reduce the gapbetween pulses in the trench (or wherever else the liquid is beingapplied).

Further, the capillary action provided by exit hose section 131 and/ordistal tip 117 helps to ensure that the application assembly 115,upstream of hose section 131 and/or distal tip 117, remain full, whenvalve 109 is closed. It can replace the need for an independent checkvalve in each application assembly 115.

Also, as liquid exits hose section 131 and/or tip 117, a jetting effectis created because the fluid is exiting at higher linear speed throughhose section 131 and/or tip 117 than it is traveling upstream inapplication assembly 115. This is because of the lower inner diameter ofexit hose section 131 and/or tip 117 relative to that of the hosesections upstream. This reduces the likelihood that the end of hose 131and/or tip 117 will be plugged.

Some parts of row unit 106 will now be discussed in more detail. First,it will be noted that there are different types of seed meters, and theone that is shown is shown for the sake of example only. For instance,in one example, each row unit 106 need not have its own seed meter.Instead, metering or other singulation or seed dividing techniques canbe performed at a central location, for groups of row units 106. Themetering systems can include rotatable discs, rotatable concave orbowl-shaped devices, among others. The seed delivery system can be agravity drop system (such as that shown in FIG. 2) in which seeds aredropped through the seed tube 120 and fall (via gravitational force)through the seed tube into the seed trench. Other types of seed deliverysystems are assistive systems, in that they do not simply rely ongravity to move the seed from the metering system into the ground.Instead, such systems actively capture the seeds from the seed meter andphysically move the seeds from the meter to a lower opening, where theyexit into the ground or trench.

A downforce actuator 126 is mounted on a coupling assembly 128 thatcouples row unit 106 to toolbar 102. Actuator 126 can be a hydraulicactuator, a pneumatic actuator, a spring-based mechanical actuator or awide variety of other actuators. In the example shown in FIG. 2, a rod130 is coupled to a parallel linkage 132 and is used to exert anadditional downforce (in the direction indicated by arrow 134) on rowunit 106. The total downforce (which includes the force indicated byarrow 134 exerted by actuator 126, plus the force due to gravity actingon row unit 106, and indicated by arrow 136) is offset by upwardlydirected forces acting on closing wheels 118 (from ground 138 andindicated by arrow 140) and double disc opener 114 (again from ground138 and indicated by arrow 142). The remaining force (the sum of theforce vectors indicated by arrows 134 and 136, minus the force indicatedby arrows 140 and 142) and the force on any other ground engagingcomponent on the row unit (not shown), is the differential forceindicated by arrow 146. The differential force may also be referred toherein as the downforce margin. The force indicated by arrow 146 acts onthe gauge wheels 116. This load can be sensed by a gauge wheel loadsensor which may be located anywhere on row unit 106 where it can sensethat load. It can also be placed where it may not sense the loaddirectly, but a characteristic indicative of that load. Both sensing theload directly or indirectly are contemplated herein and will be referredto as sensing a force characteristic indicative of that load (or force).For example, it can be disposed near a set of gauge wheel control arms(or gauge wheel arm) 148 that movably mount gauge wheels 116 to shank152 and control an offset between gauge wheels 116 and the discs indouble disc opener 114, to control planting depth. Arms (or gauge wheelarms) 148 illustratively abut against a mechanical stop (or arm contactmember-or wedge) 150. The position of mechanical stop 150 relative toshank 152 can be set by a planting depth actuator assembly 154. Controlarms 148 illustratively pivot around pivot point 156 so that, asplanting depth actuator assembly 154 actuates to change the position ofmechanical stop 150, the relative position of gauge wheels 116, relativeto the double disc opener 114, changes, to change the depth at whichseeds are planted. This is described in greater detail below.

In operation, row unit 106 travels generally in the direction indicatedby arrow 160. The double disc opener 114 opens a furrow in the soil 138,and the depth of the furrow 162 is set by planting depth actuatorassembly 154, which, itself, controls the offset between the lowestparts of gauge wheels 116 and disc opener 114. Seeds are dropped throughseed tube 120, into the furrow 162 and closing wheels 118 close thesoil.

Example 1 is a mobile agricultural machine, comprising:

ground engaging elements that carry the machine over a field;

a valve, having an inlet end configured to be connected to a source ofliquid, under pressure, to be applied to the field and an outlet end;

a pump pumping the liquid from the source to the valve; and

an application assembly having a proximal end connected to the outletend of the valve and having a distal end through which pulses of theliquid pass to be applied to the field, the application assemblydefining a conduit between the proximal end and the distal end, andhaving a first hose section with a first inner diameter defining a firstsection of the conduit and a second hose section, with a second innerdiameter, smaller than the first inner diameter, defining a secondsection of the conduit, the second section of the conduit lengtheningthe pulses of the liquid.

Example 2 is the mobile agricultural machine of any or all previousexamples wherein the valve is controlled with a pulsed control signal.

Example 3 is the mobile agricultural machine of any or all previousexamples wherein the second hose section defines the second section ofthe conduit distal of the first section of the conduit.

Example 4 is the mobile agricultural machine of any or all previousexamples wherein the second hose section extends to the distal end

of the conduit.

Example 4 is the mobile agricultural machine of claim 4 wherein thesecond hose section is configured so the inner diameter is sufficientlysmall to exhibit a capillary effect that retains the liquid in thesecond hose section when the valve is closed.

Example 6 is the mobile agricultural machine of any or all previousexamples wherein the first hose section has an inner diameter in a rangeof 6.35-12.77 mm.

Example 7 is the mobile agricultural machine of any or all previousexamples wherein the second hose section has an inner diameter in arange of 2-4 mm.

Example 8 is the mobile agricultural machine of any or all previousexamples wherein the second hose section is configured to retain itsinner diameter when the liquid under pressure is in the second sectionof the conduit.

Example 9 is the mobile agricultural machine of any or all previousexamples wherein the liquid is introduced through the valve into theconduit at a pressure in a range of 10-150 psi.

Example 10 is the mobile agricultural machine of any or all previousexamples wherein the second hose section further comprises:

an orifice member disposed on a distal tip of the first hose section anddefining an orifice that has a constant inner diameter regardless ofwhether the valve is opened or closed.

Example 11 is the mobile agricultural machine of any or all previousexamples wherein the orifice member defines the orifice with the innerdiameter in a range of 0.7-4.5 mm.

Example 12 is the mobile agricultural machine of any or all previousexamples wherein the first hose section is configured to be expandablewhen the liquid under pressure is in the first section of the conduit.

Example 13 is the mobile agricultural machine of any or all previousexamples wherein the application assembly further comprises:

a third hose section, with the first inner diameter, between the firsthose section and the second hose section, the third hose sectiondefining a third section of the conduit between the first section of theconduit and the second section of the conduit and separated from thefirst hose section by an orifice member defining an orifice with a fixedinner diameter under pressure exerted by the liquid under pressure.

Example 14 is a mobile agricultural machine, comprising:

a ground engaging element that carries the machine over a field;

a valve, having an inlet end configured to be connected to a source ofliquid, under pressure, to be applied to the field and an outlet end,the valve being controlled with a pulsed control signal; and

an application assembly having a proximal end connected to the outletend of the valve and having a distal end through which the liquid passesto be applied to the field, the application assembly defining a conduitbetween the proximal end and the distal end, and having a first hosesection with a first inner diameter defining a first section of theconduit and a second hose section, distal of the first hose section,with a second inner diameter, smaller than the first inner diameter,defining a second section of the conduit, distal of the first section ofthe conduit, wherein the second hose section is configured to retain itsinner diameter when the liquid under pressure is in the second sectionof the conduit.

Example 15 is the mobile agricultural machine of any or all previousexamples wherein the second hose section extends to the distal end ofthe conduit.

Example 16 is the mobile agricultural machine of any or all previousexamples wherein the first hose section has an inner diameter in a rangeof 6.35-12.77 mm.

Example 17 is the mobile agricultural machine of any or all previousexamples wherein the second hose section has an inner diameter in arange of 2-4 mm.

Example 18 is the mobile agricultural machine of any or all previousexamples wherein the liquid is introduced through the valve into theconduit at a pressure in a range of 10-150 psi.

Example 19 is the mobile agricultural machine of any or all previousexamples and further comprising:

an orifice member disposed on a distal tip of the second hose sectionand defining an orifice that has a constant inner diameter regardless ofwhether the valve is opened or closed.

Example 20 is a mobile agricultural machine, comprising:

a ground engaging element that carries the machine over a field;

a valve, having an inlet end configured to be connected to a source ofliquid, under pressure, to be applied to the field and an outlet end,the valve being controlled, to be opened and closed, with a pulse widthmodulated control signal; and

an application assembly having a proximal end connected to the outletend of the valve and having a distal end through which the liquid passesto be applied to the field, the application assembly defining a conduitbetween the proximal end and the distal end, and having a first hosesection with a first inner diameter defining a first section of theconduit and a second hose section, with a second inner diameter, smallerthan the first inner diameter, defining a second section of the conduitdistal of the first section of the conduit and having an orifice memberdisposed on a distal tip of the second hose section, the orifice memberdefining an orifice with an inner diameter that remains fixed regardlessof whether the valve is opened or closed.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A mobile agricultural machine, comprising: groundengaging elements that carry the machine over a field; a valve, havingan inlet end configured to be connected to a source of liquid, underpressure, to be applied to the field and an outlet end; a pump pumpingthe liquid from the source to the valve; and an application assemblyhaving a proximal end connected to the outlet end of the valve andhaving a distal end through which pulses of the liquid pass to beapplied to the field, the application assembly defining a conduitbetween the proximal end and the distal end, and having a first hosesection with a first inner diameter defining a first section of theconduit and a second hose section, with a second inner diameter, smallerthan the first inner diameter, defining a second section of the conduit,the second section of the conduit lengthening the pulses of the liquid.2. The mobile agricultural machine of claim 1 wherein the valve iscontrolled with a pulsed control signal.
 3. The mobile agriculturalmachine of claim 1 wherein the second hose section defines the secondsection of the conduit distal of the first section of the conduit. 4.The mobile agricultural machine of claim 3 wherein the second hosesection extends to the distal end of the conduit.
 5. The mobileagricultural machine of claim 4 wherein the second hose section isconfigured so the inner diameter is sufficiently small to exhibit acapillary effect that retains the liquid in the second hose section whenthe valve is closed.
 6. The mobile agricultural machine of claim 4wherein the first hose section has an inner diameter in a range of6.35-12.77 mm.
 7. The mobile agricultural machine of claim 4 wherein thesecond hose section has an inner diameter in a range of 2-4 mm.
 8. Themobile agricultural machine of claim 3 wherein the second hose sectionis configured to retain its inner diameter when the liquid underpressure is in the second section of the conduit.
 9. The mobileagricultural machine of claim 8 wherein the liquid is introduced throughthe valve into the conduit at a pressure in a range of 10-150 psi. 10.The mobile agricultural machine of claim 3 wherein the second hosesection further comprises: an orifice member disposed on a distal tip ofthe first hose section and defining an orifice that has a constant innerdiameter regardless of whether the valve is opened or closed.
 11. Themobile agricultural machine of claim 10 wherein the orifice memberdefines the orifice with the inner diameter in a range of 0.7-4.5 mm.12. The mobile agricultural machine of claim 3 wherein the first hosesection is configured to be expandable when the liquid under pressure isin the first section of the conduit.
 13. The mobile agricultural machineof claim 12 wherein the application assembly further comprises: a thirdhose section, with the first inner diameter, between the first hosesection and the second hose section, the third hose section defining athird section of the conduit between the first section of the conduitand the second section of the conduit and separated from the first hosesection by an orifice member defining an orifice with a fixed innerdiameter under pressure exerted by the liquid under pressure.
 14. Amobile agricultural machine, comprising: a ground engaging element thatcarries the machine over a field; a valve, having an inlet endconfigured to be connected to a source of liquid, under pressure, to beapplied to the field and an outlet end, the valve being controlled witha pulsed control signal; and an application assembly having a proximalend connected to the outlet end of the valve and having a distal endthrough which the liquid passes to be applied to the field, theapplication assembly defining a conduit between the proximal end and thedistal end, and having a first hose section with a first inner diameterdefining a first section of the conduit and a second hose section,distal of the first hose section, with a second inner diameter, smallerthan the first inner diameter, defining a second section of the conduit,distal of the first section of the conduit, wherein the second hosesection is configured to retain its inner diameter when the liquid underpressure is in the second section of the conduit.
 15. The mobileagricultural machine of claim 14 wherein the second hose section extendsto the distal end of the conduit.
 16. The mobile agricultural machine ofclaim 15 wherein the first hose section has an inner diameter in a rangeof 6.35-12.77 mm.
 17. The mobile agricultural machine of claim 16wherein the second hose section has an inner diameter in a range of 2-4mm.
 18. The mobile agricultural machine of claim 17 wherein the liquidis introduced through the valve into the conduit at a pressure in arange of 10-150 psi.
 19. The mobile agricultural machine of claim 18 andfurther comprising: an orifice member disposed on a distal tip of thesecond hose section and defining an orifice that has a constant innerdiameter regardless of whether the valve is opened or closed.
 20. Amobile agricultural machine, comprising: a ground engaging element thatcarries the machine over a field; a valve, having an inlet endconfigured to be connected to a source of liquid, under pressure, to beapplied to the field and an outlet end, the valve being controlled, tobe opened and closed, with a pulse width modulated control signal; andan application assembly having a proximal end connected to the outletend of the valve and having a distal end through which the liquid passesto be applied to the field, the application assembly defining a conduitbetween the proximal end and the distal end, and having a first hosesection with a first inner diameter defining a first section of theconduit and a second hose section, with a second inner diameter, smallerthan the first inner diameter, defining a second section of the conduitdistal of the first section of the conduit and having an orifice memberdisposed on a distal tip of the second hose section, the orifice memberdefining an orifice with an inner diameter that remains fixed regardlessof whether the valve is opened or closed.